using System;

using System.Linq;

​

class Program

{

    static void Main()

    {

        //take input from console

        string first = Console.ReadLine();

        string[] splitted = first.Split(' ');//split them with empty spaces

​

        int[] Arr = new int[splitted.Length];//int array for string console values

        for (int i = 0; i < splitted.Length; i++)//goes true all elements and converts them into Int32

        {

            Arr[i] = int.Parse(splitted[i]);

        }

​

        int[] novArr = new int[(Arr.Length / 2)];

        int sum = 0;

        for (int i = 0; i < Arr.Length; i += 2)

        {

            if (i + 1 < Arr.Length)

            {

                novArr[sum] = Arr[i] + Arr[i + 1];

            }

            else

            {

                novArr[sum] = Arr[i];

            }

            sum++;

        }

​

        //check if the values are equal

        int counter = 0;

        int Value = 0;

        for (int i = 0; i < novArr.Length - 1; i++)

        {

            if (novArr[i] == novArr[i + 1])

            {

                counter++;

            }

            else

            {

                int x = 0;

                int[] fibArray = new int[novArr.Length-1];

                int SumValue = 0;

​

                for (x = 0; x <= novArr.Length; x++)

                {

                    if (x + 1 < novArr.Length)

                    {

                        fibArray[SumValue] = novArr[x] - novArr[x + 1];

                    }

                    SumValue++;

                }

                Value = (fibArray.Max(element => Math.Abs(element)));

            }

        }

        if (counter == novArr.Length - 1)

        {

            Console.WriteLine("Yes, value={0}", novArr[0]);

        }

        else

        {

            Console.WriteLine("No, maxdiff={0}", Value);

        }

    }

}

​